1. Technical Field of the Invention
The present invention relates to an apparatus for supplying a flexible workpiece, and more particularly to an improvement to an apparatus for supplying a workpiece which is capable of supplying a belt-shaped flexible workpiece such as a tire tread automatically and positively to the next process, within a reduced space.
2. Description of the Prior Art
An apparatus for supplying a material for a tire tread used during the formation of green tires, such as that shown in FIG. 1, is well known. In this apparatus, the direction in which a workpiece-conveying unit 1 moves is the same as the direction in which a workpiece W (tread material) is supplied to a tire-forming drum and, because it is necessary to ensure sufficient working space for an operator, and for other reasons, the stroke of the movement of the workpiece-conveying unit 1 toward the tire-forming drum 2 from an approach position (a position at which the workpiece W is supplied onto a green tire on the tire-forming drum 2, while being centered) to a standby position (a position at which the workpiece W is mounted onto the workpiece-conveying unit 1) is long.
As a result, when the workpiece-conveying unit 1 approaches the tire-forming drum 2, the front of the workpiece-conveying unit 1, i.e., the section in the vicinity of the portion on which a centering mechanism 3 is installed, overhangs some distance beyond a frame 4. Consequently, the workpiece-conveying unit 1 is instable and rocks while it is being moved, and gaps are generated with respect to conveyer unit slide guides 5, which not only adversely affects the accuracy with which the workpiece W is attached to a belt material B but also makes it difficult to maintain the accuracy of the slide guides 5. The size of the entire apparatus is large, so that a large installation space capable of including the full operating range is necessary.
In addition, since, in a conventional apparatus, the workpiece-conveying unit 1 is installed horizontally at a fixed height, when mounting a workpiece W of a fixed length (tread material) placed on a carriage onto the workpiece-conveying unit 1, the central portion of the workpiece W, when lifted up, droops downward since the workpiece W is elastic. For this reason, when mounting the workpiece W onto the workpiece-conveying unit 1, it is necessary to lift up both ends to a considerable height, thus forcing the operator to do a laborious action, and reducing work efficiency.